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Juergen Neesen - One of the best experts on this subject based on the ideXlab platform.
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the hook1 gene is non functional in the abnormal Spermatozoon Head shape azh mutant mouse
Human Molecular Genetics, 2002Co-Authors: Irene Mendozalujambio, Peter Burfeind, C Dixkens, Andreas Meinhardt, Sigrid Hoyerfender, Wolfgang Engel, Juergen NeesenAbstract:In mice carrying the autosomal recessive mutation ‘abnormal Spermatozoon Head shape’ (azh )a ll spermatozoa display a highly abnormal Head morphology that differs drastically from the compact and hook-shaped Head of the normal murine sperm. Moreover, the azh mutation causes tail abnormalities often resulting in coiled sperm tails or in the decapitation of the sperm Head from the flagellum. We have isolated and characterized murine Hook1 cDNA and analyzed the corresponding genomic structure. Furthermore, the Hook1 gene was mapped to the same region on chromosome 4 to which the azh locus was previously linked. The Hook1 gene is predominantly expressed in haploid male germ cells, and immunohistochemical analysis revealed that Hook1 is responsible for the linkage of the microtubular manchette and the flagellum to cellular structures. Here, we report that the azh mutation is due to a deletion of exons 10 and 11 in the murine Hook1 gene leading to a non-functional protein. Our results indicate that loss of Hook1 function results in ectopic positioning of microtubular structures within the spermatid and causes the azh phenotype. Therefore, the human HOOK1 gene could serve as a candidate gene for male infertility due to teratozoospermia or decapitation defects.
Kanayama, Cláudio Yudi - One of the best experts on this subject based on the ideXlab platform.
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Testicular temperature rise and its influence on compacting chromatin and sperm morphometry in rabbits (Oryctolagus cuniculus)
Universidade Federal de Uberlândia, 2010Co-Authors: Kanayama, Cláudio YudiAbstract:Uma abordagem mais moderna sobre a elevação da temperatura foi realizada, visando detectar alterações na compactação e morfometria da cabeça do espermatozoide pela análise computacional. O objetivo do trabalho foi avaliar a compactação da cromatina e a morfometria espermática após a elevação da temperatura testicular, por meio de criptorquidismo experimental, em coelhos. Foram utilizados 30 coelhos da raça Nova Zelândia, brancos, adultos, situados no coelhário da Universidade de Uberaba, Uberaba, MG, Brasil. Os coelhos foram separados em dois grupos de 15. Ambos os grupos foram anestesiados, mas somente um deles sofreu intervenção cirúrgica, o criptorquidismo experimental. Foram coletadas amostras de sêmen durante 69 dias. Esfregaços de sêmen de todos os coelhos foram corados com azul de toluidina e, posteriormente, analisados digitalmente por meio de microcomputador para avaliar a compactação de cromatina e morfometria. A cromatina foi avaliada quanto à intensidade de compactação (Dif%), homogeneidade pelo coeficiente de variação (CV) e cromatina anômala (Cr. An.). Na análise morfométrica foram avaliados: área, perímetro (Per.), largura (Larg.), comprimento (Comp.), razão largura:comprimento (L/C), elipsidade (E), fator forma (FF), simetria lateral (Sim. Lat.), simetria ântero posterior (Sim. A-P) e descritores Fourier com amplitude de 0 a 2. A elevação da temperatura testicular influenciou negativamente a concentração, motilidade, vigor, torna-se anômala a estrutura da cromatina e a cabeça do espermatozoide tende a diminuir.One performed a more modern approach on such heat stress to find changes out to compact morphometry in Spermatozoon Head by computational analysis. One aimed in this work to assess how to compact chromatin and sperm morphometry after have risen testicular temperature, by using experimental cryptorchidism in rabbits (Oryctolagus cuniculus), as well as used 30 rabbits: wild rabbit, white, adult, located in the rabbit keeping of University of Uberaba, Uberaba (city), MG (State of Minas Gerais), Brazil. One classified the rabbits into two groups of 15. Both groups were anesthetised, but only the experimental cryptorchidism one underwent a surgical operation. One gathered semen samples within a total of 69 days. One both dyed semen smear of all rabbits by using a toluidine blue dye and afterwards analysed it with a digital microcomputer to assess compacting chromatin and sperm morphometry. Chromatin varied regarding compact intensity (Diff%), homogeneity by coefficient of variation (CV) and aberrant chromatin (AbChr). By analysing morphometrically one assessed: area, perimeter (Perim.), width (w.), length (l.), ratio width:length (w./l.), ellipsity (E.), form factor (FF), lateral symmetry (LatSym), antero-posterior symmetry (A-PSym), and Fourier descriptors with amplitude from 0 to 2. Testicular temperature rise swayed the concentration, motility, and vigour adversely. Chromatin structure becomes aberrant when affected by testicular heat stress. And Spermatozoon Head tends to lessen
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Testicular temperature rise and its influence on compacting chromatin and sperm morphometry in rabbits (Oryctolagus cuniculus)
'EDUFU - Editora da Universidade Federal de Uberlandia', 2010Co-Authors: Kanayama, Cláudio YudiAbstract:One performed a more modern approach on such heat stress to find changes out to compact morphometry in Spermatozoon Head by computational analysis. One aimed in this work to assess how to compact chromatin and sperm morphometry after have risen testicular temperature, by using experimental cryptorchidism in rabbits (Oryctolagus cuniculus), as well as used 30 rabbits: wild rabbit, white, adult, located in the rabbit keeping of University of Uberaba, Uberaba (city), MG (State of Minas Gerais), Brazil. One classified the rabbits into two groups of 15. Both groups were anesthetised, but only the experimental cryptorchidism one underwent a surgical operation. One gathered semen samples within a total of 69 days. One both dyed semen smear of all rabbits by using a toluidine blue dye and afterwards analysed it with a digital microcomputer to assess compacting chromatin and sperm morphometry. Chromatin varied regarding compact intensity (Diff%), homogeneity by coefficient of variation (CV) and aberrant chromatin (AbChr). By analysing morphometrically one assessed: area, perimeter (Perim.), width (w.), length (l.), ratio width:length (w./l.), ellipsity (E.), form factor (FF), lateral symmetry (LatSym), antero-posterior symmetry (A-PSym), and Fourier descriptors with amplitude from 0 to 2. Testicular temperature rise swayed the concentration, motility, and vigour adversely. Chromatin structure becomes aberrant when affected by testicular heat stress. And Spermatozoon Head tends to lessen.Mestre em Ciências VeterináriasUma abordagem mais moderna sobre a elevação da temperatura foi realizada, visando detectar alterações na compactação e morfometria da cabeça do espermatozoide pela análise computacional. O objetivo do trabalho foi avaliar a compactação da cromatina e a morfometria espermática após a elevação da temperatura testicular, por meio de criptorquidismo experimental, em coelhos. Foram utilizados 30 coelhos da raça Nova Zelândia, brancos, adultos, situados no coelhário da Universidade de Uberaba, Uberaba, MG, Brasil. Os coelhos foram separados em dois grupos de 15. Ambos os grupos foram anestesiados, mas somente um deles sofreu intervenção cirúrgica, o criptorquidismo experimental. Foram coletadas amostras de sêmen durante 69 dias. Esfregaços de sêmen de todos os coelhos foram corados com azul de toluidina e, posteriormente, analisados digitalmente por meio de microcomputador para avaliar a compactação de cromatina e morfometria. A cromatina foi avaliada quanto à intensidade de compactação (Dif%), homogeneidade pelo coeficiente de variação (CV) e cromatina anômala (Cr. An.). Na análise morfométrica foram avaliados: área, perímetro (Per.), largura (Larg.), comprimento (Comp.), razão largura:comprimento (L/C), elipsidade (E), fator forma (FF), simetria lateral (Sim. Lat.), simetria ântero posterior (Sim. A-P) e descritores Fourier com amplitude de 0 a 2. A elevação da temperatura testicular influenciou negativamente a concentração, motilidade, vigor, torna-se anômala a estrutura da cromatina e a cabeça do espermatozoide tende a diminuir
Irene Mendozalujambio - One of the best experts on this subject based on the ideXlab platform.
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the hook1 gene is non functional in the abnormal Spermatozoon Head shape azh mutant mouse
Human Molecular Genetics, 2002Co-Authors: Irene Mendozalujambio, Peter Burfeind, C Dixkens, Andreas Meinhardt, Sigrid Hoyerfender, Wolfgang Engel, Juergen NeesenAbstract:In mice carrying the autosomal recessive mutation ‘abnormal Spermatozoon Head shape’ (azh )a ll spermatozoa display a highly abnormal Head morphology that differs drastically from the compact and hook-shaped Head of the normal murine sperm. Moreover, the azh mutation causes tail abnormalities often resulting in coiled sperm tails or in the decapitation of the sperm Head from the flagellum. We have isolated and characterized murine Hook1 cDNA and analyzed the corresponding genomic structure. Furthermore, the Hook1 gene was mapped to the same region on chromosome 4 to which the azh locus was previously linked. The Hook1 gene is predominantly expressed in haploid male germ cells, and immunohistochemical analysis revealed that Hook1 is responsible for the linkage of the microtubular manchette and the flagellum to cellular structures. Here, we report that the azh mutation is due to a deletion of exons 10 and 11 in the murine Hook1 gene leading to a non-functional protein. Our results indicate that loss of Hook1 function results in ectopic positioning of microtubular structures within the spermatid and causes the azh phenotype. Therefore, the human HOOK1 gene could serve as a candidate gene for male infertility due to teratozoospermia or decapitation defects.
Ravaux Benjamin - One of the best experts on this subject based on the ideXlab platform.
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A specific flagellum beating mode for inducing fusion in mammalian fertilization and kinetics of sperm internalization
'Springer Science and Business Media LLC', 2016Co-Authors: Ravaux Benjamin, Garroum Nabil, Perez Eric, Willaime Hervé, Gourier ChristineAbstract:International audienceThe salient phases of fertilization are gamete adhesion, membrane fusion, and internalization of the Spermatozoon into the oocyte but the precise timeline and the molecular, membrane and cell mechanisms underlying these highly dynamical events are far from being established. The high motility of the spermatozoa and the unpredictable location of sperm/egg fusion dramatically hinder the use of real time imaging optical techniques that should directly provide the dynamics of cell events. Using an approach based on microfluidics technology, the sperm/egg interaction zone was imaged with the best front view, and the timeline of the fertilization events was established with an unparalleled temporal accuracy from the onset of gamete contact to full sperm DNA decondensation. It reveals that a key element of the adhesion phase to initiate fusion is the oscillatory motion of the sperm Head on the oocyte plasma membrane generated by a specific flagellum-beating mode. It also shows that the incorporation of the Spermatozoon Head is a two steps process that includes simultaneous diving, tilt, and plasma membrane degradation of the sperm Head into the oocyte and subsequent DNA decondensation
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Influence du battement du flagelle et de la composition lipidique du spermatozoïde sur l'étape de fusion des gamètes chez le mammifère
HAL CCSD, 2016Co-Authors: Ravaux BenjaminAbstract:Fertilization is the encounter of two gametes. Although this process is crucial for sexual organisms, the timeline of the molecular events is not yet established. The researchers cannot explain: how the Spermatozoon fuses with the oocyte? One of the reasons is the lack of experimental methods available. Indeed, the gametes need a specific environment to fertilize. Nevertheless, the scientific community identified three essential proteins: Izumo1 on the Spermatozoon, Juno (its receptor) and CD9 on the oocyte membrane. For our part, we tried to determine if the none-proteins environment of Izumo1 and CD9 could influence the gametic interaction. To do so, we were focused on the role of the lipids composition of the sperm membranes and on the influence of the forces developed by the flagellum beating on the oocyte. We designed two original experimental methods to offer a better understanding of the mechanisms inside the gamete contact area. With the first one, we tried to identify the minimal machinery to induce fusion. We started to reconstitute step by step the membrane of the Spermatozoon Head. We tested first the identified lipids alone, and then we coupled these molecules with Izumo1. With the second one, we developed a microfluidic tool to observe the gametic encounter with the “best” viewpoint in the most physiological in-vitro conditions. We observed that the flagellum beating is not only involved in the crossing of the female genital tract but also in the initiation of the fusion step. Indeed, the mechanical constraints induce membrane reorganization with CD9 recruitment. So we succeed to establish the kinetic of the events with an unequaled resolution.La fécondation est la rencontre de deux gamètes. Bien que centrale chez les espèces sexuées, les mécanismes membranaires et moléculaires ne sont pas encore établis. La communauté scientifique bute toujours sur la question centrale : Comment le spermatozoïde fusionne-t-il avec l’ovule ? Si des études ont identifié trois protéines essentielles : Izumo1, Juno et CD9, elles montrent aussi que ces acteurs ne sont pas suffisants. Notre étude a eu pour but d’identifier d’autres paramètres potentiels impliqués dans cette machinerie de fusion. Nous nous sommes donc focalisés sur la contribution des lipides spermatiques et sur celle du battement du flagelle. Nous avons développé deux méthodes expérimentales originales. Avec la première, qualifiée de « Bottom-up », nous avons tenté de déterminer la machinerie spermatique minimale pour induire la fusion avec l’ovocyte. L’idée a été de reconstituer pas à pas la membrane de la tête du spermatozoïde, d’abord avec les lipides identifiés lors d’analyses, puis en y incorporant Izumo1. Pour la seconde approche, appelée « Top-down », nous avons développé un outil microfluidique pour guider le spermatozoïde jusqu’à l’ovocyte afin de suivre la rencontre avec le « meilleur » point de vue, dans des conditions in-vitro aussi physiologiques que possible. Nous avons découvert que contrairement à ce que nous pensions, le battement du flagelle ne sert pas uniquement à atteindre l'ovocyte, mais aussi à déclencher la fécondation. En effet, les contraintes mécaniques induisent une réorganisation de la membrane ovocytaire incluant la protéine CD9. Ainsi, la chronologie des événements a pu être obtenue avec une résolution temporelle inégalée
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Effect of the flagellum beating and of the Spermatozoon lipids composition on the fusion step during mammalian gametes interaction
2016Co-Authors: Ravaux BenjaminAbstract:La fécondation est la rencontre de deux gamètes. Bien que centrale chez les espèces sexuées, les mécanismes membranaires et moléculaires ne sont pas encore établis. La communauté scientifique bute toujours sur la question centrale : Comment le spermatozoïde fusionne-t-il avec l’ovule ? Si des études ont identifié trois protéines essentielles : Izumo1, Juno et CD9, elles montrent aussi que ces acteurs ne sont pas suffisants. Notre étude a eu pour but d’identifier d’autres paramètres potentiels impliqués dans cette machinerie de fusion. Nous nous sommes donc focalisés sur la contribution des lipides spermatiques et sur celle du battement du flagelle. Nous avons développé deux méthodes expérimentales originales. Avec la première, qualifiée de « Bottom-up », nous avons tenté de déterminer la machinerie spermatique minimale pour induire la fusion avec l’ovocyte. L’idée a été de reconstituer pas à pas la membrane de la tête du spermatozoïde, d’abord avec les lipides identifiés lors d’analyses, puis en y incorporant Izumo1. Pour la seconde approche, appelée « Top-down », nous avons développé un outil microfluidique pour guider le spermatozoïde jusqu’à l’ovocyte afin de suivre la rencontre avec le « meilleur » point de vue, dans des conditions in-vitro aussi physiologiques que possible. Nous avons découvert que contrairement à ce que nous pensions, le battement du flagelle ne sert pas uniquement à atteindre l'ovocyte, mais aussi à déclencher la fécondation. En effet, les contraintes mécaniques induisent une réorganisation de la membrane ovocytaire incluant la protéine CD9. Ainsi, la chronologie des événements a pu être obtenue avec une résolution temporelle inégalée.Fertilization is the encounter of two gametes. Although this process is crucial for sexual organisms, the timeline of the molecular events is not yet established. The researchers cannot explain: how the Spermatozoon fuses with the oocyte? One of the reasons is the lack of experimental methods available. Indeed, the gametes need a specific environment to fertilize. Nevertheless, the scientific community identified three essential proteins: Izumo1 on the Spermatozoon, Juno (its receptor) and CD9 on the oocyte membrane. For our part, we tried to determine if the none-proteins environment of Izumo1 and CD9 could influence the gametic interaction. To do so, we were focused on the role of the lipids composition of the sperm membranes and on the influence of the forces developed by the flagellum beating on the oocyte. We designed two original experimental methods to offer a better understanding of the mechanisms inside the gamete contact area. With the first one, we tried to identify the minimal machinery to induce fusion. We started to reconstitute step by step the membrane of the Spermatozoon Head. We tested first the identified lipids alone, and then we coupled these molecules with Izumo1. With the second one, we developed a microfluidic tool to observe the gametic encounter with the “best” viewpoint in the most physiological in-vitro conditions. We observed that the flagellum beating is not only involved in the crossing of the female genital tract but also in the initiation of the fusion step. Indeed, the mechanical constraints induce membrane reorganization with CD9 recruitment. So we succeed to establish the kinetic of the events with an unequaled resolution
Morielle-versute Eliana - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructure of Spermatogenesis in the Short-Tailed Fruit Bat, Carollia perspicillata ( Chiroptera: Phyllostomidae: Carollinae)
Wiley-Blackwell, 2014Co-Authors: Beguelini, Mateus R., Taboga, Sebastiao R., Bueno, Larissa M., Caun, Dianelli L., Morielle-versute ElianaAbstract:Among species of the Chiroptera, spermatogenesis and the fully differentiated spermatozoa differ in morphological and ultrastructural detail. This study therefore aimed to ultrastructurally characterize the spermatogenesis and the spermatozoa of Carollia perspicillata (Phyllostomidae) and compare the process with other species of bats and mammals. The differentiation of spermatogonia is similar to other bats and to Primates, with three main spermatogonia types: A(d), A(p), and B. Meiotic divisions proceed similarly to those of most mammals and spermiogenesis is clearly divided into 12 steps, in the middle of the range of developmental steps for bats (9-16 steps). The process of acrosome formation is similar to that found in Platyrrhinus lineatus, with the acrosome formed by two different types of proacrosomal vesicles. The ultrastructure of the Spermatozoon is similar to other bats already described and resembles the typical mammalian sperm model; however, its morphology differs from other mammals such as marsupials and rodents, on account of a simpler Spermatozoon Head morphology, which indicates a pattern that is more closely related to the sperm cells of humans and other primates. Our data demonstrated that spermatogenesis in C. perspicillata presents great ultrastructural similarities to P. lineatus. This pattern is not surprising, because both species belong to the same family (Phyllostomidae); however, it is observed that C. perspicillata presents some characteristics that are more closely related to phylogenetically distant species, such as Myotis nigricans (Vespertilionidae), which is a fact that deserves attention. J. Morphol. 275:111-123, 2014. (c) 2013 Wiley Periodicals, Inc.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
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Ultrastructural characteristics of spermatogenesis in Pallas's mastiff bat, Molossus molossus (Chiroptera: Molossidae)
Wiley-Blackwell, 2012Co-Authors: Beguelini, Mateus R., Taboga, Sebastiao R., Morielle-versute ElianaAbstract:Despite the large number of species, their wide distribution, and unique reproductive characteristics, Neotropical bats have been poorly studied, and important aspects of the reproduction of these animals have not been elucidated. We made an ultrastructural analysis of spermatogenesis in Molossus molossus (Molossidae). The process of spermatogonial differentiation is similar to that found in other bats and is also relatively similar to that of Primates, with three main spermatogonia types: Ad, Ap, and B. Meiotic divisions proceed similarly to those of most mammals, and spermiogenesis is clearly divided into 12 steps, in the middle of the range known for bats (916 steps). Formation of the acrosome is similar to that known from other mammals; however, the ultrastructure of spermatozoa was found to have unique characteristics, including many wavy acrosomal projections on its surface, which seems to be specific for the family Molossidae. Comparing the ultrastructure of the Spermatozoon of M. molossus with other bats already study, we observed that three characters vary: morphology of the outer dense fibers, of the perforatorium, and of the Spermatozoon Head. The great similarity of morphological characters between M. molossus and Platyrrhinus lineatus suggests that M. molossus is more closely related to the Phyllostomidae than to the Rhinolophidae and the Vespertilionidae. Microsc. Res. Tech. 2012. (C) 2012 Wiley Periodicals, Inc.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP